Pesticide concentrations decreasing in US

October 21st, 2008 - 1:38 pm ICT by IANS  

Washington, Oct 21 (IANS) There is some good news on the pesticide front in the US, where its widespread use has been routine, but with little knowledge of the long-term effects on the nation’s groundwater. The results of a new study show that samples taken from over 300 wells across the US have not retained a high concentration of pesticide contamination. The news is a result of a decade long study to assess the extent of the impact of contaminants on the nation’s water supply.

Over the years, frequent research has detected pesticides in ground water around the country, including in aquifers used for drinking-water supply. Over the past few decades, the use of some pesticides has been restricted or banned, while new pesticides have been introduced.

One goal of the study was to track the retention of various types of contaminants that would be found in the different pesticides used over the years.

Results for one of the first national studies on the presence of pesticides in groundwater were recently published. The study is a part of that agency’s federally-funded National Water-Quality Assessment (NAWQA) Program.

“The results of this study are encouraging for the future state of the nation’s ground-water quality with respect to pesticides,” said Laura Bexfield, who conducted the data analysis, according to a release of the American Society of Agronomy.

“Despite sustained use of many popular pesticides and the introduction of new ones, results as a whole did not indicate increasing detection rates or concentrations in shallow or drinking-water resources over the 10 years studied.”

Original samples were taken from the wells from 1993-1995, and compared with samples taken from 2001-2003. Lab analysis was performed using methods that allowed detection of pesticide compounds at concentrations as small as 1,000 times below USEPA drinking-water standards.

Of the 80 compounds studied, only six were detected in ground water from at least 10 wells during both of those sample periods. Concentrations of these compounds generally were less than 0.12 parts per billion, or more than 10 times lower than applicable USEPA drinking-water standards.

This article was included as part of the 316-page Journal of Environmental Quality supplement that houses two special collections of papers: the Environmental Impacts and Sustainability of Degraded Water Reuse Symposium and USGS National Water-Quality Assessment Ground-Water Trends Program.

These findings were published by the US Geological Survey in the September-October issue of the Journal of Environmental Quality.

Tags: , , , , , , , , ,

Posted in World |